 During this time Taiaroa made a bold sortie to the Waipara, hoping to destroy the invaders' canoes, but light axes could make little impression on the heavy hull timbers of large war canoes, and torrential rain made it impossible to burn them.As the siege seemed likely to be protracted it was then decided that Taiaroa should then return to Otago and bring up reinforcements.Finding that any direct assault was to open to the fire of the defenders, Te Rauparaha set his men to sap up to the walls.